Drill bit



A. L. STONE Feb. 14, 1950 DRILL BIT 2 Sheets-Sheet 1 Filed Nov; 25, 1945#1321971. $70111 /& 23 22 24 23 3 INVEN TOR.

fir TOP/VE) A. L. STONE Feb. 14, 950

DRILL BIT 2 Sheets-Sheet 2 Filed Nov. 25, 1945 INVENTOR.

Patented Feb. 14, 1950 UNITED STATES ATENT OFFICE- DRILL BIT Albert L.Stone, Palos Verdes Estates, Calif.

Application November 23, 1945, Serial No. 630,197

8 Claims.

This invention has to do with improvements in well drilling bits,particularly rotary bits to be used for drilling rock or other hardformations presenting diflicult considerations with respect both tocutting of the formation and the removal of the severed particles orcuttings.

One major object and characteristic of the invention is the adaptationin a rotary drill bit of a rotary cutting or abrading wheel drivenindependently of the bit rotation and having certain important anddistinctive functions in relation to the cutting efiiciency of the bit.Of particular importance in contributing to that efliciency and thecapacity of the bit to penetrate hard formaion to better advanage thanthe usual bits, are (1) the cutting functions of the rotary cutter, and(2) the maintenance of fluid circulation and immediate removal ofcuttings from the formation surfaces against which the cutter acts.

In its preferred forms the present bit comprises a fluid driven rotarycutter contained in the bit body in such relation to the bottom cuttingface of the body as to be capable of high speed cutting or abradingcontact with the formation surface, or a portion thereof, being drilledaway. One main function of the cutter is to remove the formation at thecenter of the hole, thus eliminating any core that might otherwise tendto form, and also the formation at a central location where, in the caseof bits having a non-coring action as by a central or diametricallycontinuous cutting blade or face, a localized center grinding effectwould occur without adequate circulation to conduct away heat generatedby the extreme friction. The present fluid driven cutter may be centeredrelative to the hole for rotation about a transverse axis so that thebottom surface of the cutter removes at least that portion of theformation at the center of the cutting area of the bit. As will appear,the rotary cutter may be adapted to cut across the full diameter of thebore, or it may be so mounted in the bit body as to selectively workagainst a central or core area otherwise unsevered by the cutting facesof the body.

The rotary cutter may take essentially the form of a turbine or impellerwheel carrying vanes against which one or more streams of high velocitycirculating fluid are directed to drive the cutter at relatively highspeed. The wheel has peripheral cutting surfaces, as presented for example by annular side portions beyond the vanes, and by reason of theopen or vaned form of the wheel, movement of circulating fluid iscontinuously maintained at its cutting faces and across 2 the bottomsurface of the hole. Thus the effect of the fluid driven cutter is toassure constant and complete removal of cuttings with greater efficiencythan is permitted by the usual bit.

A further important feature and object of the invention is to provide animproved bit having greater hard formation drilling efilciency byincorporation of diamond particles in its cutting or abrading faces, andspecifically in the cutting surfaces of either or both the body and highspeed rotary cutter of the present type of bit. With particularreference to the cutter wheel, the presence of diamond particles in itsouter face gives the wheel, especially at high rotative speeds, capacityfor very efficient cutting or abrading action against the hardest offormations.

Certain typical embodiments of the invention shown in the accompanyingdrawings will serve more clearly to illustrate the above mentioned andfurther contemplated features and objects. Referring to the drawings:

Fig. 1 is a side elevation illustrating one embodiment of the invention;

Fig. 2 is a section on line 22 of Fig. 1;

Fig. 3 is a section on line 3-3 of Fig. 2;

Fig. 4 is a section on line 44 of Fig. 2;

Fig. 5 is a view similar to Fig. 3 illustrating a variational form ofthe invention;

Fig. 6 is a section on line 6-6 of Fig. 5;

Fig. 7 is a section on line 1--1 of Fig. 6;

Fig. 8 is a fragmentary section showing a variational form of rotarycutter; and

Fig. 9 is a section on line 9-9 of Fig. 8.

The drill bit illustrated in Figs. 1 through 4' comprises a suitablebody structure I 0 which may have any suitable means, not shown, forattachment to the usual drill string through which circulating fluid ispumped for delivery through the body bore I l to the rotary cutter aswill presently appear. Generally speaking, the body proper may bedesigned to have any suitable or specific form or arrangement of cuttingfaces rotatable against the bottom of the well bore l3 to cut theformation l4. Merely as typical, the body is shown to have curved faceportions or ribs l5 and 16 between which the body surface is channeledat ll to facilitate the flow and distribution of circulating fluid overthe cutting area of the bit.

mond particles l8 are embedded in the cutting faces of the body, itbeing understood that the diamonds may be embedded therein in anysuitable manner as by the known methods of caulking into the cuttingfaces individual diamonds, or diamond-containing metallic slugs, or byfacing the surfaces with metallic matarix containing relatively finelydivided diamond particles.

The body contains a central or axially alined vertical opening or slothaving a top arcuate surface 2| below which the sides of the slot aredefined by' and in accordance with. the curvature of the body ribportions l6 through which the slot is formed or cut. The slot 20contains a rotary cutter generally indicated at 22 preferably in theform of an impeller or turbine wheel haying spaced sides 23interconnected by curved vanes 24, the particular shapes and; extents;of which may be selected or determined to. best utilize the energy(velocity) of the fluiddirected against them to produce high speedrotation. of the cutter. chargedv from bore. H through one ormore-nozzle passages 25. against. the cutter vanes 24' to. cause.rotationof. the cutter at high speeds, the. rate. of which in.individual instances. will depend upon such. considerations. as, thefluid. pressure obtainable. at the nozzle. 25. and the fluid head.against whichthe liquidisdischarged, into the well.

The. cutter may be formedwithlsolid. or tubular trunnions. 26.journaled. for. rotation within bearings. 211. The bearings. may bespecially selected for resistance, to. abrasive. fluid, andv desi'rablymay be. made. of rubber. specifically as sleeves or other suitable.bearing. form. When hollow. or tubular, the trunnions-2B. providepassages Zllthrough which fluidlmay escape fromthe. center of thecutter. wheel into the body recesses 29 and thence upwardly into, thefluid column. in the well; As will. be. understood. Without-necessityfor specific illustration,,i the trunnions. are. solidly formed, thebody metal may be extended. to occupy all or a portion of' the. recesses25..

Proper. clearances are. maintained between the cutter and the surfaces20'- and 21 to permit free rotation.of the cutter. Referring to.Fig.,-2,.it.will be noted. that surface 2|, extended. by the bodyportion 30 forms with the curved face 3] of the hole apartial;peripheral closure about the. wheel, confining the fi'uid forapplication of its velocity force or headto the vanesfi. The clearance32maintained at theperipherali porti'onofthe cutter opposite the portion30;. permits escape of. the fluid and cuttingsbeing. carried. upwardly,by the. wheel, into the well' fluid. column,v The cutting faces .ofthe,wheel may include. the peripheral faces of'both the. annular sides, 23,.and, if. desired. the. outer edges. of the vanes. 2.4;. As.in the. caseof. the body ribs I5 and, |.6,.thev cutting, surfaces. of the. wheel maycontain embedded diamond particles 33.which,,at the high. speedof the.cutter. rotations. give the wheel highly.- efficient cutting.andabrading actionagainst the. formation.

In the. operation of. the. tool,, rotationof the. bit body producescorresponding. cutting. actionof the, curvedsurface bod-y. portions I5.and Idagainstthe. formation. Simultaneously, the. independentlydriven. cutter wheel. 22 is. given an; independent; cutting andabradingaction. againstsubstantially the=full hemispherical bottomsurfaceofthehola. A further importantfunction. of; the cutter tnconstantly maintain. a. high. velocity sweep of. circulating fluidagainst the. formation surface being acted. upon by all the cuttingfaces, resulting; in. the immediate: removal. of. cuttings; and.

dissipation of. frictionally developed heat. At.

this. point it. may: be mentionedthat the wheel;

High pressure circulating fluid is dismay be so located that itsperipheral cutting faces may be ofi-set sufflciently above the cuttingsurfaces of the body that the vertical load and pressure of the toolagainst the bottom of the hole will be assumed by the body, at least toa degree relieving the rotating cutter of bottom pressure to an extentthat it will be capable of high speed rotation under the influence ofthe fluid stream directed against it.

The variational. form of the. invention shown in Figs. 5 to 7 isgenerally similar to the described embodiment except with respect tocertain modifications in the body structure and the adaptation of therotary cutter for selectively removing a core portion of the formation.Here the body 35 has the annular bottom portions 36 forming the cuttingfaces 3.! and 38 at the outside of a central recess 39 which receives acore portion 40 of the formation as the bit progressively cuts the hole.Delivery of circulating fluid from the bore II to the cutting faces ofthe body may be effected in any suitable. manner, as for. example,through passages. 46 from which the fluid is discharged into channelsor. grooves 41,48 and 49 respectively in the. inside, bottom. andexterior cutting faces of the body portion 3.6.

The. function of the cutting. wheel 4! is to remove the core. 4 at. arate corresponding to the rate of. penetration of the bit. Asillustrated, the bottom portion of. the cutter may extend into therecess-39 below thev body surface 4H 50 as to cut the core against asegmental spherical surface 42. The cuttingsare immediately swept intothe fluid stream in the cutter to be discharged through the openings 43;Except at the bottom, the rotary cutter 41 is peripherally enclosedwithin the circular body opening dill, it being understood that ampleclearances may be maintained at all 10- cations. between the cutter andthe body to permit free. rotation of the cutter. The cutting faces ofthe body and wheel may if. desired contain embedded diamond. particlesas described with reference to Figs. 1'. to 4'.

Figs. 8 and; 9 illustrate a variational form of rotary cutter in whichthe vanes. extend inwardly to the radial center of the wheel and carryvanes 51. centered transversely of the vanes to div-ide the. fluid.stream projecting against them. Toward the. center of the. wheel thevanes widen at 52 to form bafflev surf-aces servingto deflect the fluidstreams into. the outlet passage 53 formed by, the. hollow trunnions5'4.

Itshonld be observed that the body may have any suitable. section. orother. construction permitting installation, of the rotary cutter andits bearings. and final. integration of the body.. Merely as.illustrative, initially the body in both. described forms of theinvention may be made in separate upper and lower sections, for example,aboye and below thetransverse planes of section lines l4 and; in Figs.2. and 6. After insertion of the rotary cutter and its bearings in one.of the sections, the other may be applied thereto and. the twosectionswelded together at the interfaces corresponding to the locations of. thesection lines.

I claim:

1. A well drill bit comprising a rotatable body carrying; a bottomformation cutting means, a circular'cutter carried by and rotatablewithin a central. portionof the; body to cut the formationported bytheengagement of said. cutting means.

.5-- witlrthe; formation the=cutter is. thereby permitted relativelyhigh speed rotation, and means for rotating said cutter at suchrelatively high speed independently of the body rotation.

2. A well drill bit comprising a rotatable body having a bottom cuttingface, a circular cutter carried by and rotatable within a centralportion of the body to cut the formation at the center of the cuttingarea of said body face while the body and cutter are verticallysupported by the engagement of said cutting means with the formation andthe cutter is thereby permitted relatively high speed rotation, andmeans for rotating said cutter at such relatively high speed by fluidpressure independently of the body rotation.

3. A well drill bit comprising a rotatable body having a bottomformation cutting face, a circular cutter carried by and rotatablewithin a central opening in the body about a transverse axis while thebody and cutter are vertically supported by the engagement of saidcutting means with the formation and the cutter is thereby permittedrelatively high speed rotation, vanes carried by the cutter, and meansdirecting fluid against said vanes to rotate the cutter, said formationcutting face of the body being curved substantially in accordance withthe curvature of said cutter.

4. A well drill bit comprising a rotatable body having a bottomformation cutting face, a circular cutter carried by and rotatablewithin a central opening in the body about a transverse axis While thebody and cutter are vertically supported by the engagement of saidcutting means with the formation and the cutter is thereby permittedrelatively high speed rotation, said cutter having spaced sides havingbottom cutting contact with the formation, vanes extending between saidsides, and means directing fluid against said vanes to rotate the cutterat such relatively high speed.

5. A well drill bit comprising a rotatable body having a bottomformation cutting face, a circular cutter carried by and rotatablewithin a central opening in the body about a transverse axis while thebody and cutter are vertically supported by the engagement of saidcutting means with the formation and the cutter is thereby permittedrelatively high speed rotation, said cutter having spaced sides havingbottom cutting contact with the formation, vanes extending between saidsides, diamonds embedded in the peripheral surfaces of said sides, andmeans directing fluid against said vanes to rotate the cutter at suchrelatively high speed.

6. A well drill bit comprising a rotatable body carrying bottomformation cutting means, a circular cutter carried by and rotatablewithin a central opening in the body about a transverse axis while thebody and cutter are vertically supported by the engagement of saidcutting means with the formation and the cutter is thereby permittedrelatively high speed rotation, said cutter having bottom cuttingcontact with the formation throughout a substantially semi-circularextent of the cutter, vanes carried by the cutter, and means directingfluid against said vanes to rotate the cutter at such relatively highspeed.

7. A Well drill bit comprising a rotatable body having a bottomformation cutting face, a circular cutter carried by and rotatablewithin a central opening in the body about a transverse axis while thebody and cutter are vertically supported by the engagement of saidcutting means with the formation and the cutter is thereby permittedrelatively high speed rotation, said cutter having bottom cuttingcontact with the formation at a location above said bottom cutting faceof the body, vanes carried by the cutter, and means directing fluidagainst said vanes to rotate the cutter at such relatively high speed.

8. A well drill bit comprising a rotatable body having a bottomformation cutting face, a circular cutter carried by and rotatablewithin a central opening in the body about a transverse axis while thebody and cutter are vertically supported by the engagement of saidcutting means with the formation and the cutter is thereby permittedrelatively high speed rotation, said cutter having bottom cuttingcontact with the forma- 1- tion, trunnions supporting the cutter andjournaled in lateral openings in the body, vanes carried by the cutters,and means directing the fluid against said vanes to rotate the cutter atsuch relatively high speed, said trunnions containing openings throughwhich fluid leaving said vanes escapes.

ALBERT L. STONE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,391,626 Gilthorpe Sept. 20,1921 1,870,592 Schuerman Aug. 9, 1932 2,034,073 Wright Mar. 17, 19362,184,066 Zublin Dec. 19, 1939 2,207,187 Zublin July 9, 1940 2,268,775Potvin Jan. 6, 1942

